Make sure `createuser and createsuperuser` work

src/servala/core/models/user.py

@@ -1,11 +1,36 @@
-from django.contrib.auth.models import AbstractBaseUser
+from django.contrib.auth.models import AbstractBaseUser, BaseUserManager
 from django.db import models
 from django.utils.translation import gettext_lazy as _
 
 
+class UserManager(BaseUserManager):
+    """
+    Use a separate model manager, as we do not have a username field.
+    """
+
+    use_in_migrations = True
+
+    def create_user(self, email, password, **extra_fields):
+        if not email:
+            raise ValueError("Please provide an email address.")
+        email = self.normalize_email(email)
+        user = self.model(email=email, **extra_fields)
+        user.set_password(password)
+        user.save(using=self._db)
+        return user
+
+    def create_superuser(self, email, password, **extra_fields):
+        """Create and save a SuperUser with the given email and password."""
+        extra_fields["is_staff"] = True
+        extra_fields["is_superuser"] = True
+        return self.create_user(email, password, **extra_fields)
+
+
 class User(AbstractBaseUser):
     """The Django model provides a password and last_login field."""
 
+    objects = UserManager()
+
     email = models.EmailField(unique=True, verbose_name=_("Email address"))
     first_name = models.CharField(
         max_length=30, blank=True, verbose_name=_("First name")